1 wpa_supplicant and Hotspot 2.0 2 ============================== 3 4 This document describe how the IEEE 802.11u Interworking and Wi-Fi 5 Hotspot 2.0 (Release 1) implementation in wpa_supplicant can be 6 configured and how an external component on the client e.g., management 7 GUI or Wi-Fi framework) is used to manage this functionality. 8 9 10 Introduction to Wi-Fi Hotspot 2.0 11 --------------------------------- 12 13 Hotspot 2.0 is the name of the Wi-Fi Alliance specification that is used 14 in the Wi-Fi CERTIFIED Passpoint<TM> program. More information about 15 this is available in this white paper: 16 17 http://www.wi-fi.org/knowledge-center/white-papers/wi-fi-certified-passpoint%E2%84%A2-new-program-wi-fi-alliance%C2%AE-enable-seamless 18 19 The Hotspot 2.0 specification is also available from WFA: 20 https://www.wi-fi.org/knowledge-center/published-specifications 21 22 The core Interworking functionality (network selection, GAS/ANQP) were 23 standardized in IEEE Std 802.11u-2011 which is now part of the IEEE Std 24 802.11-2012. 25 26 27 wpa_supplicant network selection 28 -------------------------------- 29 30 Interworking support added option for configuring credentials that can 31 work with multiple networks as an alternative to configuration of 32 network blocks (e.g., per-SSID parameters). When requested to perform 33 network selection, wpa_supplicant picks the highest priority enabled 34 network block or credential. If a credential is picked (based on ANQP 35 information from APs), a temporary network block is created 36 automatically for the matching network. This temporary network block is 37 used similarly to the network blocks that can be configured by the user, 38 but it is not stored into the configuration file and is meant to be used 39 only for temporary period of time since a new one can be created 40 whenever needed based on ANQP information and the credential. 41 42 By default, wpa_supplicant is not using automatic network selection 43 unless requested explicitly with the interworking_select command. This 44 can be changed with the auto_interworking=1 parameter to perform network 45 selection automatically whenever trying to find a network for connection 46 and none of the enabled network blocks match with the scan results. This 47 case works similarly to "interworking_select auto", i.e., wpa_supplicant 48 will internally determine which network or credential is going to be 49 used based on configured priorities, scan results, and ANQP information. 50 51 52 wpa_supplicant configuration 53 ---------------------------- 54 55 Interworking and Hotspot 2.0 functionality are optional components that 56 need to be enabled in the wpa_supplicant build configuration 57 (.config). This is done by adding following parameters into that file: 58 59 CONFIG_INTERWORKING=y 60 CONFIG_HS20=y 61 62 It should be noted that this functionality requires a driver that 63 supports GAS/ANQP operations. This uses the same design as P2P, i.e., 64 Action frame processing and building in user space within 65 wpa_supplicant. The Linux nl80211 driver interface provides the needed 66 functionality for this. 67 68 69 There are number of run-time configuration parameters (e.g., in 70 wpa_supplicant.conf when using the configuration file) that can be used 71 to control Hotspot 2.0 operations. 72 73 # Enable Interworking 74 interworking=1 75 76 # Enable Hotspot 2.0 77 hs20=1 78 79 # Parameters for controlling scanning 80 81 # Homogenous ESS identifier 82 # If this is set, scans will be used to request response only from BSSes 83 # belonging to the specified Homogeneous ESS. This is used only if interworking 84 # is enabled. 85 #hessid=00:11:22:33:44:55 86 87 # Access Network Type 88 # When Interworking is enabled, scans can be limited to APs that advertise the 89 # specified Access Network Type (0..15; with 15 indicating wildcard match). 90 # This value controls the Access Network Type value in Probe Request frames. 91 #access_network_type=15 92 93 # Automatic network selection behavior 94 # 0 = do not automatically go through Interworking network selection 95 # (i.e., require explicit interworking_select command for this; default) 96 # 1 = perform Interworking network selection if one or more 97 # credentials have been configured and scan did not find a 98 # matching network block 99 #auto_interworking=0 100 101 102 Credentials can be pre-configured for automatic network selection: 103 104 # credential block 105 # 106 # Each credential used for automatic network selection is configured as a set 107 # of parameters that are compared to the information advertised by the APs when 108 # interworking_select and interworking_connect commands are used. 109 # 110 # credential fields: 111 # 112 # priority: Priority group 113 # By default, all networks and credentials get the same priority group 114 # (0). This field can be used to give higher priority for credentials 115 # (and similarly in struct wpa_ssid for network blocks) to change the 116 # Interworking automatic networking selection behavior. The matching 117 # network (based on either an enabled network block or a credential) 118 # with the highest priority value will be selected. 119 # 120 # pcsc: Use PC/SC and SIM/USIM card 121 # 122 # realm: Home Realm for Interworking 123 # 124 # username: Username for Interworking network selection 125 # 126 # password: Password for Interworking network selection 127 # 128 # ca_cert: CA certificate for Interworking network selection 129 # 130 # client_cert: File path to client certificate file (PEM/DER) 131 # This field is used with Interworking networking selection for a case 132 # where client certificate/private key is used for authentication 133 # (EAP-TLS). Full path to the file should be used since working 134 # directory may change when wpa_supplicant is run in the background. 135 # 136 # Alternatively, a named configuration blob can be used by setting 137 # this to blob://blob_name. 138 # 139 # private_key: File path to client private key file (PEM/DER/PFX) 140 # When PKCS#12/PFX file (.p12/.pfx) is used, client_cert should be 141 # commented out. Both the private key and certificate will be read 142 # from the PKCS#12 file in this case. Full path to the file should be 143 # used since working directory may change when wpa_supplicant is run 144 # in the background. 145 # 146 # Windows certificate store can be used by leaving client_cert out and 147 # configuring private_key in one of the following formats: 148 # 149 # cert://substring_to_match 150 # 151 # hash://certificate_thumbprint_in_hex 152 # 153 # For example: private_key="hash://63093aa9c47f56ae88334c7b65a4" 154 # 155 # Note that when running wpa_supplicant as an application, the user 156 # certificate store (My user account) is used, whereas computer store 157 # (Computer account) is used when running wpasvc as a service. 158 # 159 # Alternatively, a named configuration blob can be used by setting 160 # this to blob://blob_name. 161 # 162 # private_key_passwd: Password for private key file 163 # 164 # imsi: IMSI in <MCC> | <MNC> | '-' | <MSIN> format 165 # 166 # milenage: Milenage parameters for SIM/USIM simulator in <Ki>:<OPc>:<SQN> 167 # format 168 # 169 # domain: Home service provider FQDN 170 # This is used to compare against the Domain Name List to figure out 171 # whether the AP is operated by the Home SP. 172 # 173 # roaming_consortium: Roaming Consortium OI 174 # If roaming_consortium_len is non-zero, this field contains the 175 # Roaming Consortium OI that can be used to determine which access 176 # points support authentication with this credential. This is an 177 # alternative to the use of the realm parameter. When using Roaming 178 # Consortium to match the network, the EAP parameters need to be 179 # pre-configured with the credential since the NAI Realm information 180 # may not be available or fetched. 181 # 182 # eap: Pre-configured EAP method 183 # This optional field can be used to specify which EAP method will be 184 # used with this credential. If not set, the EAP method is selected 185 # automatically based on ANQP information (e.g., NAI Realm). 186 # 187 # phase1: Pre-configure Phase 1 (outer authentication) parameters 188 # This optional field is used with like the 'eap' parameter. 189 # 190 # phase2: Pre-configure Phase 2 (inner authentication) parameters 191 # This optional field is used with like the 'eap' parameter. 192 # 193 # for example: 194 # 195 #cred={ 196 # realm="example.com" 197 # username="user (a] example.com" 198 # password="password" 199 # ca_cert="/etc/wpa_supplicant/ca.pem" 200 # domain="example.com" 201 #} 202 # 203 #cred={ 204 # imsi="310026-000000000" 205 # milenage="90dca4eda45b53cf0f12d7c9c3bc6a89:cb9cccc4b9258e6dca4760379fb82" 206 #} 207 # 208 #cred={ 209 # realm="example.com" 210 # username="user" 211 # password="password" 212 # ca_cert="/etc/wpa_supplicant/ca.pem" 213 # domain="example.com" 214 # roaming_consortium=223344 215 # eap=TTLS 216 # phase2="auth=MSCHAPV2" 217 #} 218 219 220 Control interface 221 ----------------- 222 223 wpa_supplicant provides a control interface that can be used from 224 external programs to manage various operations. The included command 225 line tool, wpa_cli, can be used for manual testing with this interface. 226 227 Following wpa_cli interactive mode commands show some examples of manual 228 operations related to Hotspot 2.0: 229 230 Remove configured networks and credentials: 231 232 > remove_network all 233 OK 234 > remove_cred all 235 OK 236 237 238 Add a username/password credential: 239 240 > add_cred 241 0 242 > set_cred 0 realm "mail.example.com" 243 OK 244 > set_cred 0 username "username" 245 OK 246 > set_cred 0 password "password" 247 OK 248 > set_cred 0 priority 1 249 OK 250 251 Add a SIM credential using a simulated SIM/USIM card for testing: 252 253 > add_cred 254 1 255 > set_cred 1 imsi "23456-0000000000" 256 OK 257 > set_cred 1 milenage "90dca4eda45b53cf0f12d7c9c3bc6a89:cb9cccc4b9258e6dca4760379fb82581:000000000123" 258 OK 259 > set_cred 1 priority 1 260 OK 261 262 Note: the return value of add_cred is used as the first argument to 263 the following set_cred commands. 264 265 266 Add a WPA2-Enterprise network: 267 268 > add_network 269 0 270 > set_network 0 key_mgmt WPA-EAP 271 OK 272 > set_network 0 ssid "enterprise" 273 OK 274 > set_network 0 eap TTLS 275 OK 276 > set_network 0 anonymous_identity "anonymous" 277 OK 278 > set_network 0 identity "user" 279 OK 280 > set_network 0 password "password" 281 OK 282 > set_network 0 priority 0 283 OK 284 > enable_network 0 no-connect 285 OK 286 287 288 Add an open network: 289 290 > add_network 291 3 292 > set_network 3 key_mgmt NONE 293 OK 294 > set_network 3 ssid "coffee-shop" 295 OK 296 > select_network 3 297 OK 298 299 Note: the return value of add_network is used as the first argument to 300 the following set_network commands. 301 302 The preferred credentials/networks can be indicated with the priority 303 parameter (1 is higher priority than 0). 304 305 306 Interworking network selection can be started with interworking_select 307 command. This instructs wpa_supplicant to run a network scan and iterate 308 through the discovered APs to request ANQP information from the APs that 309 advertise support for Interworking/Hotspot 2.0: 310 311 > interworking_select 312 OK 313 <3>Starting ANQP fetch for 02:00:00:00:01:00 314 <3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 315 <3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 316 <3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 317 <3>ANQP fetch completed 318 <3>INTERWORKING-AP 02:00:00:00:01:00 type=unknown 319 320 321 INTERWORKING-AP event messages indicate the APs that support network 322 selection and for which there is a matching 323 credential. interworking_connect command can be used to select a network 324 to connect with: 325 326 327 > interworking_connect 02:00:00:00:01:00 328 OK 329 <3>CTRL-EVENT-SCAN-RESULTS 330 <3>SME: Trying to authenticate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 331 <3>Trying to associate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 332 <3>Associated with 02:00:00:00:01:00 333 <3>CTRL-EVENT-EAP-STARTED EAP authentication started 334 <3>CTRL-EVENT-EAP-PROPOSED-METHOD vendor=0 method=21 335 <3>CTRL-EVENT-EAP-METHOD EAP vendor 0 method 21 (TTLS) selected 336 <3>CTRL-EVENT-EAP-SUCCESS EAP authentication completed successfully 337 <3>WPA: Key negotiation completed with 02:00:00:00:01:00 [PTK=CCMP GTK=CCMP] 338 <3>CTRL-EVENT-CONNECTED - Connection to 02:00:00:00:01:00 completed (auth) [id=0 id_str=] 339 340 341 wpa_supplicant creates a temporary network block for the selected 342 network based on the configured credential and ANQP information from the 343 AP: 344 345 > list_networks 346 network id / ssid / bssid / flags 347 0 Example Network any [CURRENT] 348 > get_network 0 key_mgmt 349 WPA-EAP 350 > get_network 0 eap 351 TTLS 352 353 354 Alternatively to using an external program to select the network, 355 "interworking_select auto" command can be used to request wpa_supplicant 356 to select which network to use based on configured priorities: 357 358 359 > remove_network all 360 OK 361 <3>CTRL-EVENT-DISCONNECTED bssid=02:00:00:00:01:00 reason=1 locally_generated=1 362 > interworking_select auto 363 OK 364 <3>Starting ANQP fetch for 02:00:00:00:01:00 365 <3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 366 <3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 367 <3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 368 <3>ANQP fetch completed 369 <3>INTERWORKING-AP 02:00:00:00:01:00 type=unknown 370 <3>CTRL-EVENT-SCAN-RESULTS 371 <3>SME: Trying to authenticate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 372 <3>Trying to associate with 02:00:00:00:01:00 (SSID='Example Network' freq=2412 MHz) 373 <3>Associated with 02:00:00:00:01:00 374 <3>CTRL-EVENT-EAP-STARTED EAP authentication started 375 <3>CTRL-EVENT-EAP-PROPOSED-METHOD vendor=0 method=21 376 <3>CTRL-EVENT-EAP-METHOD EAP vendor 0 method 21 (TTLS) selected 377 <3>CTRL-EVENT-EAP-SUCCESS EAP authentication completed successfully 378 <3>WPA: Key negotiation completed with 02:00:00:00:01:00 [PTK=CCMP GTK=CCMP] 379 <3>CTRL-EVENT-CONNECTED - Connection to 02:00:00:00:01:00 completed (reauth) [id=0 id_str=] 380 381 382 The connection status can be shown with the status command: 383 384 > status 385 bssid=02:00:00:00:01:00 386 ssid=Example Network 387 id=0 388 mode=station 389 pairwise_cipher=CCMP <--- link layer security indication 390 group_cipher=CCMP 391 key_mgmt=WPA2/IEEE 802.1X/EAP 392 wpa_state=COMPLETED 393 p2p_device_address=02:00:00:00:00:00 394 address=02:00:00:00:00:00 395 hs20=1 <--- HS 2.0 indication 396 Supplicant PAE state=AUTHENTICATED 397 suppPortStatus=Authorized 398 EAP state=SUCCESS 399 selectedMethod=21 (EAP-TTLS) 400 EAP TLS cipher=AES-128-SHA 401 EAP-TTLSv0 Phase2 method=PAP 402 403 404 > status 405 bssid=02:00:00:00:02:00 406 ssid=coffee-shop 407 id=3 408 mode=station 409 pairwise_cipher=NONE 410 group_cipher=NONE 411 key_mgmt=NONE 412 wpa_state=COMPLETED 413 p2p_device_address=02:00:00:00:00:00 414 address=02:00:00:00:00:00 415 416 417 Note: The Hotspot 2.0 indication is shown as "hs20=1" in the status 418 command output. Link layer security is indicated with the 419 pairwise_cipher (CCMP = secure, NONE = no encryption used). 420 421 422 Also the scan results include the Hotspot 2.0 indication: 423 424 > scan_results 425 bssid / frequency / signal level / flags / ssid 426 02:00:00:00:01:00 2412 -30 [WPA2-EAP-CCMP][ESS][HS20] Example Network 427 428 429 ANQP information for the BSS can be fetched using the BSS command: 430 431 > bss 02:00:00:00:01:00 432 id=1 433 bssid=02:00:00:00:01:00 434 freq=2412 435 beacon_int=100 436 capabilities=0x0411 437 qual=0 438 noise=-92 439 level=-30 440 tsf=1345573286517276 441 age=105 442 ie=000f4578616d706c65204e6574776f726b010882848b960c1218240301012a010432043048606c30140100000fac040100000fac040100000fac0100007f04000000806b091e07010203040506076c027f006f1001531122331020304050010203040506dd05506f9a1000 443 flags=[WPA2-EAP-CCMP][ESS][HS20] 444 ssid=Example Network 445 anqp_roaming_consortium=031122330510203040500601020304050603fedcba 446 447 448 ANQP queries can also be requested with the anqp_get and hs20_anqp_get 449 commands: 450 451 > anqp_get 02:00:00:00:01:00 261 452 OK 453 <3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 454 > hs20_anqp_get 02:00:00:00:01:00 2 455 OK 456 <3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 457 458 In addition, fetch_anqp command can be used to request similar set of 459 ANQP queries to be done as is run as part of interworking_select: 460 461 > scan 462 OK 463 <3>CTRL-EVENT-SCAN-RESULTS 464 > fetch_anqp 465 OK 466 <3>Starting ANQP fetch for 02:00:00:00:01:00 467 <3>RX-ANQP 02:00:00:00:01:00 ANQP Capability list 468 <3>RX-ANQP 02:00:00:00:01:00 Roaming Consortium list 469 <3>RX-HS20-ANQP 02:00:00:00:01:00 HS Capability List 470 <3>ANQP fetch completed 471
